Screw-driving machine



S. K. BROWN.

SCREW DRIVING MACHINE.

APPLICATION FILED NOV. I. I9I6.

Patented Nov. 4, 1919.

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APPLICATION FILED NOV. 7. l9l6.

Patented Nov. 4, 1919.

2 SHEETS-SHEET 2 Laz w'm wlv INVENTOR BY dwufi 7////// ur///////// w ATTOP/VE Y 8 SPENCER K. BROWN, OF SYRACUSE, NEW YORK.

SCREW-DRIVING MACHINE.

Specification of Letters Patent.

Patented Nov. 4, 1919.

Application filed November 7, 1916. Serial No. iso,o41.

Z '0 all whom it may concern:

Be it known that I, SPENCER K. BROWN, a citizen of the United States,anda resident of Syracuse, in the county of Onondaga and State of New York,have invented a certain new and useful Screw-Drivi Machine, of which thefollowing is a speci cation.

This invention relates to screw driving machines and has for its objecta particularlysimple and efficient construction by which the screw isrelieved when it has been driven to its final position and whereby it isimmediately released of the driving force when the feeding pressureceases, so that marring of the head of the screw is avoided; and theinvention consists in the combinations and constructions hereinafter setforth and claimed. In describing this invention, reference is had to theaccompanying drawings in which like characters designate correspondingparts in all the views.

Figure .1 is an elevation of-a portion of a f screw driving machineembodying my invention.

Fig. 2 is a longitudinal sectional view taken on the plane of line 2-2,Fig. 1.

Figs. 3 and 4 are enlarged sectional views taken on line 3-'-3, Fig. 2,looking in opposite directions.

Fig. 5 is a cross sectional view through the driving member.

Figs. 6 and 7 are respectively fragmentary sectional views and endelevations of the driven member when formed with a socket for hexagonalheads.

This screw driving machine comprises, generally, a guide for the screw,means for feeding the screws to the guide, mechanism for driving thescrew including two sections, one ection including an axially movablemember, actuating means connected to the other section, a frictionclutch connecting the sections, a driven member movable axially to feedthe screw engaging tool, a positive clutch connecting said members, thedriving member having an axial movement relatively to the driven memberto engage and disengage the clutch, means tending to.

normallyseparate said members and'to disengage the clutch, and means forfeeding the driving and driven members axially.

1 designates the frame of the upper portion of a screw driving machinewhich frame is provided with a suitable foot 2 for attachment to a mainframe or base.

3 designates the guide or holder for the screw, this guide or holderbeing supported by a bracket 4 suitably secured to the frame 1.

6 deslgnates a magazine chute by which the screwsare fed to the guide 3,the chute being 'connected at its lower end to a nipple 7 projecting atan inclined angle from the guide 3. The screws are fed one by one downthe magazine chute 6 in any well known manner, and as this feature formsno partof this invention, and as the construction of such means is wellknown to those skilled in the art, further description 1s thought to beunnecessary, it being sufficlent to mention that during each upwardaxial feeding movement of the driving and driven members .of the screwdriving mechanism, a screw is fed down the chute in front of the lowerend of the driven member 1n posltion to be engaged by the drivenmember'during its next downward movement.

8 designates the driving member of the screw driving mechanism and 9 thedriven member, these driving and driven members 8, 9 being arranged inaxial alinement and movable axially to advance the screw, and towithdraw the driven member from the screw after the screw is fullydriven. Said driven member 9 has its lower end normally arranged in thescrew holder or guide 3 above the passage of the nipple 7 at the pointit opens into the nipple 3, and said driven member moves across thelower end 11 of said passage during the feeding of the screw.

The driven member 9 may be provided with a detachable tool 12 forengaging .-a slotted screw head, or with a tool 13 having a socket forengaging a cap screw, as shown in Figs. 6 and 7. The screw is held inposition to receive the screw driving tool by means of spring pressedpuppets or balls 14 movable radially into the guide 3.

The clutch connecting the driven and driving members 8, 9 as here shown,includes interlocking teeth 15, 16 provided respectively on the opposingends of the members 8. 9. the teeth 15 being pins extending parallel tothe axis of the members 8, 9, from a head 17 on the member 8, and theteeth 16 on the-member 9 being the projecting ends of a pin extendingdiametrically through the upper end of the member 9 and located in anannular recess in a head 18. The heads 17 18 are connected together bysuitable fastening members 19, and the member 9 is slidable in the head18 during the relative axial movement of the members 8, 9.

20 designates a spring located in a socketin the head 17 and pressing inopposite directions on the head and on the upper end of the member 9,and normally separating said members and holding the clutch teeth 15 and16 disengaged. I

The head 17 is secured to the member 8 by means of a threaded shank 21screwing into an axial socket in the lower end of the member 8.

22 is the driving section of the screw driving mechanism, the drivingsection 22 and the member 8 are connected together by a friction clutch,the member 8 being movable axially relatively to the section 22 and thefriction clutch.' As here shown, the driving section 22 is a gear wheelwhich is connected to a gear 23 mounted on the main driving shaft 24 bygears 25, 26 mounted on a shaft 27 The driving member 8 extends throughthe bore of the gear 22 and slides axially therein and the gear 22 isprovided on its 1 upper face with an annular cavity 29 which is coveredby a cap 30; and the friction clutch, with the spring for holding thesame normally compressed is located in this cavity.

The friction clutch is here shown as a disk clutch including a set ofdisks 31 connected to the gear 22 to rotate therewith by means of ribsor flutes 32 extending in peripheral notches in the disks 31, and disks33 interleaved with the disks 31 and having tongues 34enteringperipheral grooves 35 in the driving member 8-.

The disks are held compressed together by means of a spring 36 pressing.at one end, against a compression plate 37 which compresses the disktogether, and at its other end against an axially adjustable plug 38threading into the cap 30. The plug 38 is held in its adjusted positionby means of a lock nut 39.

The bearing for the member 8 in the gear 22.is rendered oil tight bymeans of a lead bushing 40 encircling the member 8 and having a headlocated in the countersunk recess in the upper side of the gear 22, thelead being poured into the bearing around the member 8, a washer 41 isinterposed between the bearing 40 and the lower disk 34. The gear 22 isformed with a suitable hub 42 journaled in the bearing provided in 'abracket 43 forming part of the main frame 1, the hub having a collar 44'at its lower end for taking the upward thrust on-the gear 22.

The means for moving the driving and driven members 8, 9 axiallycomprises a lever 45 pivoted between its ends at 46 to a rocking fulcrumwhich in turn is pivoted at 47 to the main frame of the machine,

the lever being connected at its front end to the upper end of themember 8 and at its rear end to a link 48 which is connected at itslower end to a pedal not shown.

In operation, the members 8, 9 are constantly rotating, and the screw isfirst fed from the magazine into the chute 6 to the holder 3 where it isheld by the spring pressed puppets 14. The foot pedal is then depressedto actuate the lever 45 which in turn moves the drivin and drivenmembers 8, 9 downwardly a'xialTy until the end of the driven member 9engages the screw held by the puppets 14 and further pressure moves thescrew past the. puppets to the work.

When the resistance of the work to the screw prevents further pushing ofthe screw, additional pressure on the pedal causes the driving member 8to depress relatively to the driven member against the action of thespring 20 and thus engage the clutch pin 15, 16 whereupon the screw isdriven.

In case the tool is not in position to fit the slot or the cap of thescrew when said tool first engages the screw, it will fit the slot orthe .cap when the member 9 is turned part of a revolution. When thescrew is completely driven and the operator is still holding his foot onthe pedal the friction disk clutch will slip.

When the operator releases his foot after the screw is driven, thespring 20 causes the clutch pins 15, 16 to instantly disengage so thatturning force is not transmitted to the tool and hence the tool will notmutilate the head of the screw when being taken out of engagementtherewith.

What I claim is:

1. A screw driving machine comprising a frame, an element including twosections, actuating means connected to one section and the other sectionincluding upper and lower members, a friction clutch connecting. thesaid sections and the upper member of the said other section, said othersection being movable axially relatively to the 'fricr tion clutch, anormally open positive clutch connecting the upper and lower members,the

positive clutch being movable into clutching engagement during relativeaxial movement of the upper and lower members when the lower memberengages the screw and a .1

spring tending to separate the positive clutch sections, substantiallyas and for the purpose described.

2. A screw driving machine comprising a driving element including twosections, actuating means connected to one section, the other sectioncomprising a spindle movable axially relatively to the former section,means connected to the axially movable section for engaging the screw,the section connected to the actuating means comprising a body having acentral bore and a cavlty coaxial with the bore, the spindle of theaxially movable section extending through the bore and the cavity, adisk clutch connecting the sections and located in the cavity, the disksconnected to the axially movable section being slidably connectedthereto to permit axial feeding of the driven section, and a spring inthe cavity tending to compress the disks, substantially as and for thepurpose described.

3. A screw driving machine comprising :a driving element including twosections, actuating means connected to one section, the other sectioncomprising a spindle movable axially relatively to the former section,means connected to the axially movable section for engaging the screw,the section connected to the actuating means comprising a body havin a.central bore and a cavity coaxial wit the bore, the spindle of theaxially movable section extending through the bore and the cavity, adisk clutch connecting the sections and located in the cavity, the disksconnected to the axially movable section "being slidably connectedthereto to permit axial feeding of the driven section, a sprin in thecavity tendin to compress the dlsks, the spring encirc ing the axiallymovable section, and an adjustable abutment for one end of the spring,the abutment encircling the axially movable section and threading intothe other section, Eubastantially as and for the purpose speci- Intestimony whereof, I have hereunto signed my name, at Syracuse, in thecounty of Onondaga, and State of New York, this 19th day of October,1916.

SPENCER K. BROWN.

